动植物分类任务中的左侧半球优势

目的利用神经心理学方法比较人类对动植物类别的加工速度与大脑功能偏侧化的关系。方法要求25名右利手被试分别用声音反应和按键反应方式判别刺激属于动物或植物。在按键反应任务中,按左手-动物,右手-植物规则及相反规则各完成一次。结果被试在声音反应任务中对动物做出判断的反应时显著短于对植物做出判断的反应时(t=-3.77,P<0.001)。在按键反应任务中,被试对动植物做出判断的反应时差异受到左/右手的调制。右手按键对动物做出判断的反应时显著短于对植物做出判断的反应时(t=-3.98,P<0.001)。结论本研究初步验证了人脑对动植物分类具有不同的加工机制,并且发现动植物分类的加工机制与人脑的功能偏侧化有联系。

Lateralization of brain processing in animal/plant categorization task

Objective Categorizing external stimuli in cognitive processing is a basic principle in the brain mechanism. Numerous studies have suggested different brain mechanisms in processing natural vs. artificial objects. However, few studies have explored the difference in brain mechanism in processing animals and plants, although they play different roles in human evolution. To examine the difference in their processing mechanisms, we employed neuropsychological approach to compare the speed of judgment on nouns belonging to animals or plants. We also examined the relationship between functional lateralization of the brain and the difference in processing animals and plants. Methods Twenty-five right-handed participants (healthy college female subjects, 20~25 years old) were asked to categorize 120 single-character nouns belong to either animals or plants. The subjects were instructed to respond with speech in one session, and response with button presses in the other two. In the first button-press session, left hand corresponded to animals, and right hand corresponded to plants. The correspondence was switched in the last session. Results In the speech-response session, the reaction time (RT) in responding to animals was significantly shorter than that to plants (t=-3.77, P<0.001). In the button-press sessions, a significantly faster RT for animals than plants (t=-3.98,P<0.001) was observed with the right-hand response. Conclusion Our study provided primary but initial evidence showing the brain mechanisms in processing animals and plants are different. Relationships between the functional lateralization of the brain and the processing mechanisms for animals and plants were also observed.